1. Field of the Invention The present invention relates to a process for producing a norcamphane dicarbonitrile (hereinafter referred to as ("NDC").
NDC's may be used as intermediates for organic synthesis. For example, NDC's can be used for producing useful diamines such as bis (aminomethyl) norcamphanes (hereinafter referred to as "BAN's") of general formula (y), ##STR1## and R.sub.2 are hydrogen or aminomethyl and RI and R.sub.2 are different.
BAN's can be used directly as epoxy resin curing agents. They may be also used for producing polyamide resins by reaction with aliphatic dicarboxylic acids. Or, BAN's can be converted to diisocyanates by treating with phosgene. Diisocyanates are useful for various reactions.
2. Description of Related Art
In the past only two processes for producing NDC's by hydrocyanation of bicyclo [2,2,1[-5-heptene-2-carbonitrile (hereinafter referred to as "BHC") were known. (i) First, there is a process using a catalyst system comprising a cobalt carbonyl catalyst and triphenyl phosphine (see U.S. Pat. Nos. 2,666,780 and 2,666,748, and J. Am. Chem. Soc., 76, 5364 (1954)). In the other process (ii) a catalyst system is used which comprises tetrakis (triphenyl phosphite) palladium and triphenyl phosphite (see J. Chem. Soc. Chem. Commun., 1969, 112 and Am. Chem. Soc. Div. Pat. Chem. Preprints, 14, B29 (1969)).
Hydrocyanation of other substrate oIefins is disclosed, for example, in U.S. Pat. No. 3,773,809. In that process (iii) there is a hydrocyanation of 3-pentenenitrile and 4-pentenenitrile in the presence of a catalyst system of a zerovalent nickel complex and triarylboron; and also involves extracting and isolating the remaining active catalyst components from the resulting crude product fluid and recirculating.
U.S. Pat. No. 3,818,068 discloses a process (iv) for removing a deactivated catalyst species from a crude product fluid similar to (iii) above.
In process (i) above, the cobalt catalyst and triphenyl phosphine are used in amounts of 31 wt. % and 15 wt. %, respectively, based On the substrate olefin, BHC. Hydrogen cyanide is used in an amount of 1.4 times the mole amount of BHC, and the yield of NDC's is 62% when the reaction is effected at 130.degree. C. for 8 hours. In process (ii) above, an expensive palladium catalyst is used. Thus, the initial investment and running costs are high.
In process (iii) above, the amount of the catalysts is relatively large based on the substrate olefin subjected to hydrocyanation. Therefore, recovery and recirculation of the remaining active catalyst components are necessary.
In process (iv) above, in addition to recovery and recirculation of the active catalyst component as in process (iii), removing deactivated catalyst species is required. Effecting the procedures of (iii) and (iv) is complicated and a large investment cost is necessary.
Conventional processes have various problems, and a simple and economical process for producing NDC's is in demand.